Al Qaeda's deputy leader called on Muslims around the world to back Hamas with weapons, money and attacks on U.S. and Israeli interests in a Web audiotape Monday, urging the Palestinian militant group to unite with Al Qaeda's "holy warriors" after its takeover of Gaza.

The message from Ayman al-Zawahiri, who is Usama bin Laden's top deputy, marked a major shift by Al Qaeda, which in the past criticized Hamas for for a government with the U.S.-supported Fatah faction.

The audiotape was clearly made after Hamas' takeover of Gaza earlier this month, marking a rapid response from Al Qaeda's top leadership to the events. Its authenticity could not be independently confirmed, but it was posted on a Web forum where al-Zawahiri has issued messages in the past.

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Al-Zawahiri urged Hamas to implement Islamic law in Gaza, telling it, "Taking over power is not a goal but a means to implement God's word on earth."

"Unite with mujahedeen (holy warriors) in Palestine ... and with all mujahedeen in the world in the face of the upcoming attack where Egyptians and Saudis are expected to play part of it," he added, suggesting that the two countries intend to ttack Hamas to uproot its control of Gaza.

"Provide them (Hamas) with money, do your best to get it there, break the siege imposed on them by crusaders and Arab leaders traitors," al-Zawahiri, who is Usama bin Laden's top deputy, said, addressing Muslims around the world. "Facilitate weapons smuggling from neighboring countries."

"We can support them by targeting the crusader and Zionist interest wherever we can," al-Zawahiri said.